This disclosure relates to the field of drains for liquid flows, and more particularly to a removable floor drain grating having a mechanism for locking the grating in place over a drain pipe and which is unlocked only by use of a tool so as to prevent casual removal of the grating which may lead to undesired clogging due to drain pipe stuffing, that is, allowing large amounts of materials to enter the drain pipe. The same locking mechanism may be used with a cover for sealing the open end of a drain pipe or any similar pipe when the grating is replaced with a cover plate without any pass-through apertures, i.e., without openings therein.
A drain grating or covering is conceived as a plate that may be fitted over a drain pipe or conduit, and which may have plural openings in it, each generally smaller than the span of the drain pipe itself. Its purpose is to prevent large items from entering the drain pipe which may clog it. A grate may also be constructed as a series of spaced apart rigid bars as a lattice or as a screen such as one made of expanded metal sheeting or the like. In general, a drain grate is a filter. Drain grates usually become covered or engaged with the large items which they are designed to prevent from entering the drain pipe so that they must be periodically cleared which may require temporary removal from the drain pipe. In commercial kitchens, floors are generally hosed down to assure meeting cleanliness standards. Items such as foodstuffs, packaging materials, and the like are carried by water flows to floor drains and if allowed to enter the drain pipes, clogs may occur. To prevent this, such items must be removed from the drain grate manually in order to have a free flow of water. Kitchen help may resort to removing a drain grate in order to allow such items to enter the drain pipe thereby shortening kitchen cleanup time. This practice often results in drain pipe clogging requiring expensive steps in clearing such clogs. To help prevent this, a locking drain pipe grating may be used; one that is not easily removed. The prior art discloses various means for locking a cover onto a drain or other cylindrical conduit including types described in the following. As said, such locking mechanisms are equally useful in sealing a cover plate onto the end of a pipe to prevent anything from passing into or out of the pipe.
The prior art discloses a ratchet type closet flange for replacing broken cast iron closet flanges in old buildings or in new construction in place of conventional cast iron closet flanges. Such a device includes a flange body, a cup, a rubber seal, and a means for applying pressure such as a central bolt. After removing the broken closet flange, the ratchet type closet flange is inserted into the existing pipe. A compression seal is formed between the flange body and the inside of the pipe by applying pressure to the flange body and the cup using a central bolt, thereby forcing a compression relationship between the rubber seal and the pipe. The ratchet type closet flange may slide up and down inside the pipe to achieve a desired height.
The prior art also discloses various drain covers with looking mechanisms including those having a cylindrical body with a peripheral sidewall. Wedge members are movable from a release position to a locking position by use of a central screw or jacking mechanism. In the release position each wedge member is positioned at one end of the peripheral sidewall. In the locking position each wedge member is moved upwardly into contact with an opposing end of the peripheral sidewall so that an exterior surface of the peripheral sidewall wedges within the cylindrical body.
The presently described apparatus incorporates an advance over prior art concepts providing a locking grating or sealing cover with novel benefits in manufacture and operation as will be described below.